Research On The Hydrodynamic Performance Of Composite Ship Based On T-wing

With the development of the times and technology,the maritime trade between countries has developed rapidly.Not only the number of ships has increased,but various ship types have also emerged.In addition to bringing about economic growth in various countries,high-volume trade has also caused frequent maritime accidents.The safety of sailing ships has been paid more and more attention,and various methods to reduce the probability of capsizing of ships have appeared in our field of vision.Among them,the more eye-catching methods are the method of improving the hull profile and the method of adding anti-rolling appendages.The hull profile improvement method has certain restrictions.Many ship designs are inherently very purposeful,and their ship types cannot be significantly modified.Therefore,adding anti-rolling method has become a common choice for designers.As a relatively new type of roll stabilization appendage,T-Foil began to appear in our daily research.The research work in this article mainly focuses on the roll stabilization effect of T-shaped hydrofoil on monohull.In this paper,based on the open source CFD software OpenFOAM,the numerical models of the non-hydrofoil additional monohull,the two-dimensional airfoil and the adaptive T-Foil monohull composite boat in the flow field are respectively established.First,the average Reynolds number equation and the continuity equation are used as the governing equations to establish a calculation model,and the finite volume method is used to discretize the governing equations to study the effects of ship speed(Froude number),wave height and wavelength on the hydrodynamic characteristics of a monohull.The pitch motion characteristics of medium-sized ships are the focus of research.The second step is to design and design a T-shaped hydrofoil that meets the requirements through data reference and airfoil lift-drag characteristics.In the third step,in order to consider the coupling mechanism between the movement of the hull and the hydrofoil,as well as the interference effect of the hull on the hydrofoil and the influence of the free surface,a T-Foil is attached to the bottom of the monohull,and the VOF is used to capture the freedom.The surface effects are compared with the hydrodynamic characteristics of the monohull before and after the T-Foil,and the influence of the T-Foil’s angle of attack and size changes on the pitch and heave motion characteristics of the ship is studied.And finally design a new type of automatic roll stabilization hydrofoil.It is found that:In the study,it is found that the motion response of a single ship depends on the ship’s speed,natural frequency and the wavelength of the flow field in which it is located.When the natural frequency and encounter frequency are equal,resonance phenomenon will occur,and the motion amplitude of the ship reaches the maximum at this time.In addition,when the hydrofoil is installed,the roll stabilization performance and heavy stabilization performance of the hydrofoil are affected by the external flow field,the Angle of attack of the hydrofoil and the size of the hydrofoil.The hydrodynamic characteristics of ships with different angles of attack are obviously different.It is also found in the study that the effect of reducing sway and reducing heave of hydrofoil is greatly related to the Froude number Fr of the ship.For example,for the ship type selected in this paper,the effect of roll stabilization of large-sized hydrofoil is better when Fr is set at 0.2 and 0.4,but the effect of heavy stabilization is better only when the wave height is set at 0.12m.When Fr is 0.6,the large-size hydrofoil not only does not improve the ship stability,but also intensifies the ship motion.Therefore,different angles of attack and sizes of T-Foil should be selected according to the actual sea conditions and ship types.